Currently, wireless subscriber profile data is configured in a home location register (HLR). The home location register resides either on an end office telephony switch (EOTS) or in an off-board node that supports IS-41 protocol signaling. The subscriber data profile is retrieved from the home location register upon registration and stored in a visitor location register (VLR) while the subscriber is active. In this scenario, the base station controller does not have knowledge of the subscriber's network service profile.
The present invention addresses several shortcomings of the current configuration. First, the present invention has the ability to provide services to a wireless subscriber from a single switching node, regardless of where the mobile is currently located in the network. The biggest challenge with providing business group functionality for a mobile subscriber is addressing how the service can be configured across multiple network nodes as the mobile moves from place to place. The present invention provides a mechanism to handle all services from a single switch point by providing a voice over IP (VoIP) connection between the mobile's serving base station controller and its home switch.
Second, the present invention has the ability to perform intra-network and inter-system handoffs without impacting the network switches that are involved in the call. Voice over IP (VoIP) provides a means to re-map call control and voice signaling without using physical trunking through the network. This also allows for multiple handoffs within a specific call without the need for additional physical trunking resources between the different switches serving the call. With the present invention, only the home switch and the base station controller currently serving the mobile are involved in the call.
Third, the present invention provides a mechanism which allows wireline services to be applied transparently to wireless subscribers. The VoIP interface between the base station controller and the serving end office switch permits wireless originations to be viewed as BRI originations which allows the BRI service suite to be applied to the call.
Other approaches using a T1 connection between the base station controller and the serving switch have been tried but do not provide the flexibility to reconfigure voice and call control signaling to the extent possible with voice over IP protocols such as H.323, H.225, H.245, SIP, and MGCP.